An investigation into the Relationship between the Multiple Sclerosis Impact Scale (MSIS-29) and Predicted Medication Adherence as Measured by the Morisky Medication Adherence Scale (MMAS-8) in People with Multiple Sclerosis (P4.373)

Objective: To examine the specific relationships between global and subscale scores of the MSIS-29 and MMAS-8 in people with Multiple Sclerosis (PwMS) Background: (PwMS) have multiple treatment choices for disease modifying therapies (DMT). DMT non-adherence and treatment delay impacts outcomes and costs. Adherence can be measured by patient report, observation and refills. With varied DMT choices, routes and frequency, predicted PwMS adherence behavior needs exploration as this might impact choice. Non-adherence factors (purposeful vs. accidental) remains unexplored in PwMS. MMAS-8, a validated 8 point questionnaire, is predictive of: medication adherence, pharmacy fill data, and efficacy, economic outcomes, and can be graded to analyze purposeful and accidental sub-scores of non-adherence. This information, when paired with disability measures, might improve both understanding and addressing PwMS non-adherence, and perhaps resultant related disease progression. Design/Methods: Retrospective reviews of PwMS who completed MSIS-29 and MMAS-8 on the same day in the course of routine clinical care. Global scores for each scale, MSIS-29 physical and cognitive subscales, and MMAS-8 purposeful and accidental subscales were included. Multivariate regression analysis was used to analyze the relationships between scales. Significance was set at p Results: 245 PwMS; average age=49.8±10.8, 73.5% female. Significant relationships were as follows: MSIS-29 global with MMAS-8 global (r=0.19, p Conclusions: Factors in non-adherence in MS is complex and the most consistent relationships was between accidental non-adherence and self-reported cognitive impairment. Providers should consider therapies that are not self-administered when prescribing DMT to cognitively impaired PwMS. Disclosure: Dr. Hamid has nothing to disclose. Dr. Gudesblatt has nothing to disclose. Dr. Underwood has nothing to disclose. Dr. Wissemann has nothing to disclose. Dr. Fafard has nothing to disclose. Dr. Srinivasan has nothing to disclose. Dr. Bumstead has nothing to disclose. Dr. Buhse has nothing to disclose. Dr. Zarif has nothing to disclose. Dr. Blitz-Shabbir has nothing to disclose. Dr. Morisky has nothing to disclose.